On one hand, a whisk broom technique as a scanning technology by using a sensor can be used for meteorological observation. However, the whisk broom technology allows space information to be obtained without complicated calculation by scanning the atmosphere in a straight line, but it has a problem of causing spatial distortion due to a difference of an angle between a sensor and a scanned trajectory.
On the other hand, a conical scan technique, as a technology of shooting images while rotating conically, does not cause the spatial distortion due to a difference of an angle, but has a problem in that it requires two motors to calibrate measured meteorological data. For example, on the assumption that a meteorological sensor is mounted on an air vehicle, it is necessary to adopt a first motor for applying a rotational force to the meteorological sensor to make the meteorological sensor scan conically while the meteorological sensor is looking downwards and at the same time it is necessary to adopt a second motor for applying a rotational force to the meteorological sensor to make the meteorological sensor be placed upwards to thereby obtain a comparative value for calibrating the meteorological data. For reference, a reason for obtaining the comparative value when the meteorological sensor is looking upwards will be explained by using an example of “temperature” data. On the assumption that the air vehicle with the meteorological sensor moves in the lower stratosphere, since it is known to the public that the temperature in the lower stratosphere is constant, the corresponding constant may be set as a reference value and a temperature data measured by the meteorological sensor while the meteorological sensor is looking upwards (i.e., looking the lower stratosphere) may be used as the comparative value to be compared with the reference value. By using a difference between the reference value and the comparative value, meteorological data measured when the meteorological sensor is looking downwards could be calibrated. For example, if it is assumed that the reference value is −56.5° C. and the comparative value is −55.5° C., it can be estimated that the meteorological sensor measures the temperature data higher by 1° C. Therefore, the meteorological sensor may be under the state of receiving more heat by 1° C. Accordingly, the temperature data acquired when the meteorological sensor is looking downwards, i.e., toward the troposphere, must be calibrated as much as −1° C.
As the measurement of meteorological data by using the conical scan technique does not cause spatial distortion, the conical scan technique is more generally used than the whisk broom technique, but it has a drawback in that it needs two motors to calibrate the meteorological data. Accordingly, the conical scan technique has problems of the increased loads and the increased costs. Thus, the inventor intends to suggest an apparatus for meteorological observation that may successfully perform calibration of the meteorological data by using only one motor without any spatial distortion.